The goal of this project is to develop organ and replicative epithelial cell culture models from fresh bronchial tissue of the inbred Syrian hamster. Comparative studies utilizing the in vivo and the two in vitro models will be made to investigate the activity of selected carcinogens at the cell, tissue and whole animal levels. Emphasis will be placed on response to carcinogens at the cell level as measured by altered response to serum and growth factors, loss of anchorage-dependence, and morphological and karyotpic changes. Organ and cell cultures will be established from normal and carcinogen-treated hamsters with the aim of identifying early induced changes and in determining their relative importance in multistage carcinogenesis.